In its current, carved-up state, the Korean peninsular looks a curious construction; a cold war hangover bisected, with the north still under the sway of the communist east and the south overseen by the capitalist west. Fittingly, Park Chan Wook's Joint Security Area, which opened this year's Korean film festival, is itself split. The basic plotline of this pungent military drama (a stolid reworking of the A Few Good Men formula) comes tightly tailored in the Hollywood style. Its interior, by contrast, is airy, subtle and playful, and showcases the best elements of modern Asian cinema. At times it feels like two movies crushed into the same stretch of celluloid.

Writer-director Wook cut his teeth shooting cheap, zippy gangster flicks. This is more ambitious, a humane examination that plays out predominantly in the JSA, a demilitarised zone created by the UN as a wedge between North and South Korea. The hook is an investigation into a gun battle involving soldiers from either side conducted by Lee Young Ae's pensive UN lawyer. The set-up offers a rash of crude expository dialogue that fills us in on the historical background.

But Wook's picture comes into its own in its lyrical portrait of the friendship that develops between the rival soldiers (exchanging addresses, porn mags and photographs of girlfriends back home), and its satirical swipes at a single nation artificially split in two. When an American tourist on the southern side has her cap blown three feet across the border, it requires a North Korean soldier to pass it back to her. In this way Wook paints the division as bogus, ludicrous; like a line drawn down the middle of a bedroom by rivalrous siblings who can't recall what their original quarrel was about.

Refused permission to shoot in the actual JSA, Wook instead oversaw the construction of Korea's biggest, most expensive film set (US$800,000, 26,000 sq metres). The gamble paid off. The fascinating Joint Security Area opened to rave reviews and record-breaking receipts at the South Korean box office. Its divided tone is clearly one that native audiences can relate to.